Manufacturers and designers of integrated circuits continue to relentlessly decrease the size of integrated-circuit features, such as transistors and signal lines, and correspondingly increase the density at which features can be fabricated within integrated circuits. However, manufacturers and designers have begun to approach fundamental physical limits that prevent further decreasing feature sizes in integrated circuits fabricated by conventional photolithography techniques. Research efforts have, during the past decade, turned to new, non-photolithography-based techniques for fabricating nanoscale electronics that represent a significant decrease in feature sizes from currently available, submicroscale electronics fabricated by currently available high-resolution photolithographic techniques.
In one approach to designing and fabricating nanoscale electronics, nanowire crossbars, including multiple layers of nanowires with molecular-scale widths, are fabricated by self-assembly of nanowires on surfaces. Nanowires may also be fabricated using nanoimprinting techniques. The grid-like nanowire crossbars provide a two-dimensional array of nanowire junctions representing the closest point of contacts between nanowires of a first layer, oriented in a first direction, and nanowires of a second layer, oriented in a second direction approximately perpendicular to the first direction. The nanowire junctions may be fabricated to have properties of configurable resistors, switches, diodes, transistors, and other familiar electronic components of integrated circuits.
Many different prototype nanoscale electronic circuits have been produced in research environments, and continued research efforts are producing ever-increasing palates of nanoscale-electronic components, component organizations, and fabrication methods for producing the components and component organizations. However, practical, commercial electronic devices need to include large scale and microscale components and circuits that interface to nanoscale electronic devices and circuitry. However, devising and fabricating reliable and cost-effective interfaces between microscale and submicroscale electronics and nanoscale electronics has proven to be difficult. Therefore, researchers and developers of mixed-scale electronic devices continue to seek more reliable and more easily fabricated nanoscale/microscale interfaces for use in mixed-scale electronic devices.